You use firewalls to enhance security by denying unauthorized access to resources. Depending on the location of the firewall, you must open firewall ports to permit communication among EPM System components. For example, if you use a firewall between Oracle HTTP Server and clients (browsers), you must ensure that the port that Oracle HTTP Server uses for external communication is open on the firewall. Similarly, if you deploy a firewall between Oracle HTTP Server and WebLogic Server, ensure that the ports that EPM System components use for server-to-server communications are open on the firewall.
See Oracle Hyperion Enterprise Performance Management System Installation Start Here for a list of ports that EPM System components use.